Real Brilliance Sustainability Value

No More 4C's for Lab-Diamonds

Your synthetic diamond grading report from the Gemological Institute of America (GIA) is gearing up for big changes in 2025.

This press release from GIA (dated June 2, 2025) marks a significant shift in how laboratory-grown diamonds will be evaluated and reported by the Institute.

There will be no more 4C’s for lab diamonds.

Here’s a breakdown of the most important takeaways and implications:

Key points of the GIA's announcement to no longer use the 4C's for lab-diamonds

1. GIA is ending the use of traditional color and clarity grading (e.g., D-Z, IF-I3) for lab-grown diamonds.

These scales were originally created exclusively for natural diamonds and will now remain that way.
GIA acknowledges that over 95% of lab-grown diamonds cluster tightly within a narrow band of high color and clarity, making the full natural scale less meaningful in this context.

2. New Descriptive Categories: "Premium" and "Standard"

Instead of using specific letter/number grades, lab-grown diamonds will now be categorized as either Premium or Standard, based on a mix of color, clarity, and finish metrics.

If a lab-grown diamond doesn’t meet the minimum criteria, it won’t receive any quality designation at all—only a lab-grown confirmation.

3. Reason for the Change:

To prevent confusion between natural and lab-grown diamond reports.

To reflect the market reality that most lab-grown diamonds fall within a tight quality range.

To maintain the integrity of the natural diamond grading system, which was developed in the 1940s and is still considered the global standard.

4. Transition Timeline:

The revised system will roll out later in 2025, with full pricing and submission guidelines expected by late Q3.

Current lab-grown reports remain valid until the new system is in place.

Implications for the Industry:

For Jewelers & Retailers:

This change clearly separates natural and lab-grown diamond narratives. Marketing materials and sales training will need to reflect the new terminology.

If your business relies on traditional GIA grading for lab-grown diamonds, you may want to secure reports under the current system before the change takes effect.

Expect consumers to ask what “Premium” or “Standard” means—so educational efforts will be important.

For Consumers:

This makes it easier to distinguish between natural and lab-grown diamonds.

The simplified categorization may actually reduce confusion for non-expert buyers.

For Lab-Grown Diamond Producers:

There will be a higher bar to qualify for the “Premium” designation.
Lack of a designation could become a sales disadvantage—emphasizing the need for better production quality.